Top 10 CNN Hero Aaron Valencia's life was on a dangerous path before custom cars helped set him in the right direction. Today he works to keep youth in Los Angeles on track. Watch CNN Heroes: An All-Star Tribute, Sunday, Dec. 17 at 8 pm ET.

Top 10 CNN Hero Rosie Mashale is a former school teacher who found an abandoned child on her doorstep in 2000. Since then, she has raised a generation of AIDS orphans. Cast your vote for the CNN Hero of the Year at CNNHeroes.com and watch CNN Heroes: An All-Star Tribute, Sunday, Dec. 17 at 8 pm ET.